The invention relates to power transmissions and particularly to a control device to adjust the input torque of a hydraulic variable displacement pump.
In U.S. Pat. No. 3,742,820 to Lonnemo, input torque of a hydraulic variable displacement pump is limited, where the return spring of the control valve (or compensator) is manually set on a preload which determines the pressure limit of the control device. Since the compensator is mounted on or near to the pump casing, such setting is not by a remote control device.
It is sometimes advantageous with machines not to use the full drive power, but to limit the drive energy to the amount required at that time. The obvious result in a reduction in power consumption.